Influences of Land Use on Greenhouse Gas Fluxes within Mixed Landscapes

Abstract:

Human activities (e.g., urbanization, land use planning) have led to complex patterns of urban, suburban, agricultural, and forested landscapes. Ecosystems within these landscapes play an important role in climate regulation by acting as regulators of CO₂ and other greenhouse gases and altering surface albedo and other biophysical properties. The overarching goal of our work is to examine the interactions among carbon cycling, land use, and climate change in a human-dominated, mixed land use region that includes urban, suburban, agriculture, and forest land uses. We combine field measurements of carbon storage and greenhouse gas emissions (CO₂, CH₄, and N₂O), an improved process-based biogeochemical model - DNDC (DeNitrification and DeComposition) designed to predict C fluxes and trace gas emissions, and historical and projected land use change data derived from Landsat imagery and cellular automata/agent-based modeling. Our specific objectives designed to achieve the overarching goal are to: (1) Measure C pools and greenhouse gas emissions (CO₂, CH₄, and N₂O) in urban, suburban, agricultural, and forested landscapes; (2) Improve and parameterize the DNDC (DeNitrification and DeComposition) model and validate model predictions; (3) Develop historical land use change data for the last three decades from Landsat imagery and projections of future land use change; (4) Generate spatially continuous predictions of C pools and greenhouse gas emissions using Urban-DNDC and assess how land use interacts with C cycling and climate change and how future land use change will influence carbon sequestration potential within these complex landscapes. Our results will have implications for crafting effective land management policies that balance C sequestration and climate mitigation with food production, forest resources and many other services that these landscapes provide.